NAME
fstab, mtab - static file system mounting table, mounted
file systems table
SYNOPSIS
/etc/fstab
/etc/mtab
DESCRIPTION
The /etc/fstab file contains entries for file systems and
disk partitions to mount using the mount(8) command, which
is normally invoked by the rc.boot script at boot time.
This file is used by various utilities that mount, unmount,
check the consistency of, dump, and restore file systems.
It is also used by the system itself when locating the swap
partition.
The /etc/mtab file contains entries for file systems
currently mounted, and is read by programs using the rou-
tines described in getmntent(3). umount(8) removes entries
from this file; mount adds entries to this file.
Each entry consists of a line of the form:
filesystem directory type options freq pass
filesystem
is the pathname of a block-special device, the
name of a remote file system in host:pathname
form, or the name of a "swap file" made with
mkfile(8).
directory is the pathname of the directory on which to mount
the file system.
type is the file system type, which can be one of:
4.2 to mount a block-special device
lo to loopback-mount a file system
nfs to mount an exported NFS file system
swap to indicate a swap partition
ignore to have the mount command ignore the
current entry (good for noting disk
partitions that are not being used)
rfs to mount an RFS file system
tmp file system in virtual memory
hsfs to mount an ISO 9660 Standard or High
Sierra Standard with Rock Ridge
extensions CD-ROM file system
options contains a comma-separated list (no spaces) of
mounting options, some of which can be applied to
all types of file systems, and others which only
apply to specific types.
4.2 options:
quota|noquota Disk quotas are enforced or not
enforced. The default is
noquota.
nfs options:
bg|fg If the first attempt fails, retry in
the background, or, in the fore-
ground.
noquota Prevent quota(1) from checking
whether the user is over quota on
this file system; if the file system
has quotas enabled on the server,
quotas will still be checked for
operations on this file system.
retry=n The number of times to retry the
mount operation.
rsize=n Set the read buffer size to n bytes.
wsize=n Set the write buffer size to n bytes.
timeo=n Set the NFS timeout to n tenths of a
second.
retrans=n
The number of NFS retransmissions.
port=n The server IP port number.
soft|hard
Return an error if the server does
not respond, or continue the retry
request until the server responds.
intr Allow keyboard interrupts on hard
mounts.
secure Use a more secure protocol for NFS
transactions.
acregmin=n
Hold cached attributes for at least n
seconds after file modification.
acregmax=n
Hold cached attributes for no more
than n seconds after file modifica-
tion.
acdirmin=n
Hold cached attributes for at least n
seconds after directory update.
acdirmax=n
Hold cached attributes for no more
than n seconds after directory
update.
actimeo=n
Set min and max times for regular
files and directories to n seconds.
noac Suppress attribute caching.
Regular defaults are:
fg,retry=10000,timeo=7,retrans=3,port=NFS_PORT,hard,\
acregmin=3,acregmax=60,acdirmin=30,acdirmax=60
actimeo has no default; it sets acregmin,
acregmax, acdirmin and acdirmax
Defaults for rsize and wsize are set inter-
nally by the system kernel.
rfs options:
bg|fg If the first attempt fails,
retry in the background, or, in
the foreground.
retry=n The number of times to retry
the mount operation.
Defaults are the same as for NFS.
hsfs options:
norrip Disable processing of Rock
Ridge extensions for the file
system.
Common options:
ro|rw mount either read-only or read-write
suid|nosuid
setuid execution allowed or disal-
lowed
grpid Create files with BSD semantics for
propagation of the group ID. With
this option, files inherit the group
ID of the directory in which they are
created, regardless of the
directory's setgid bit.
noauto Do not mount this file system
automatically (using `mount -a').
freq is the interval (in days) between dumps.
pass indicates whether fsck(8) should check the parti-
tion. File systems with pass 0 are not checked.
When preening the file systems in /etc/fstab,
fsck(8) automatically overlaps file system checks
by simultaneously running one process per disk.
If run in ``force'' mode (-f), fsck checks file
systems with pass 1 sequentially, then overlaps
the remainder of the file systems checks. In
general, only the root (/) and /usr file systems
need to be checked in pass 1, with others checked
in the second pass.
A hash-sign (#) as the first character indicates a comment
line which is ignored by routines that read this file. The
order of records in /etc/fstab is important because fsck,
mount, and umount process the file sequentially; an entry
for a file system must appear after the entry for any file
system it is to be mounted on top of.
EXAMPLES
In this example, two partitions on the local disk are 4.2
mounted. Several /export directories are loopback mounted
to appear in the traditional file system locations on the
local system. The /home/user directory is hard mounted
read-write over the NFS, along with additional swap space
in the form of a mounted swap file (see System and Network
Administration for details on adding swap space):
/dev/xy0a / 4.2 rw,noquota 1 1
/dev/xy0b /usr 4.2 rw,noquota 1 1
/export/tmp/localhost /tmp lo rw 0 0
/export/var/localhost /var lo rw 0 0
/export/cluster/sun386.sunos4.0.1 /usr/cluster lo rw 0 0
/export/local/sun386 /usr/local lo rw 0 0
example:/home/user /home/user nfs rw,hard,fg 0 0
/export/swap/myswap swap swap rw 0 0
FILES
/etc/fstab
/etc/mtab
SEE ALSO
swapon(2), getmntent(3), lofs(4S), fsck(8), mkfile(8),
mount(8), quotacheck(8), quotaon(8), swapon(8)
System and Network Administration